ISPConfig not seeing external IP

I have an HP Server that I have ISPConfig 3 setup on with CentOS 5.8, the install and setup has been pretty smooth so far, but my only snag is I can not access the ISPConfig login screen using the external IP, only the local... Any suggestions?

i created a mail user [email protected] and logged into webmail, sent an email to my hotmail account, then went to hotmail and sent one back to my webmail account, but I never recveived it, I checked the maillog file and I cant see anything that looks amiss. of cousrse im not sure what to look for.